This thesis focuses on the study, implementation and improvement of a digital controller for a power factor correction (PFC) converter. The development of the telecommunications industry and the Internet demands reliable, cost-effective and intelligent power. Nowadays, the telecommunication power systems have output current of up to several kilo amperes, consisting of tens of modules. The high-end server system, which holds over 100 CPUs, consumes tens of kilowatts of power. For mission-critical applications, communication between modules and system controllers is critical for reliability. Information about temperature, current, and the total harmonic distortion (THD) of each module will enable the availability of functions such as dynamic temperature control, fault diagnosis and removal, and adaptive control, and will enhance functions such as current sharing and fault protection. The dominance of analog control at the modular level limits system-module communications. Digital control is well recognized for its communication ability. Digital control will provide the solution to system-module communication for the DC power supply. The PFC converter is an important stage for the distributed power system (DPS). Its controller is among the most complex with its three-loop structure and multiplier/divider. This thesis studies the design method, implementation and cost effectiveness of digital control for both a PFC converter and for an advanced PFC converter. Also discussed is the influence of digital delay on PFC performance. A cost-effective solution that achieves good performance is provided. The effectiveness of the solution is verified by simulation. The three level PFC with range switch is well recognized for its high efficiency. The range switch changes the circuit topology according to the input voltage level. Research literature has discussed the optimal control for both range-switch-off and range-switch-on topologies. Realizing optimal analog control requires a complex structure. Until now optimal control for the three-level PFC with analog control has not been achieved. Another disadvantage of the three-level PFC is the output capacitor voltage imbalance. This thesis proposes an active balancing solution to solve this problem. / Master of Science

The effectiveness of an EMI filter is closely related to the impedance of the noise source. Due to the time-varying nature of the noise source impedance of an offline power supply, the measurement of it cannot be done using conventional impedance measuring methods. Two new methods, the insertion loss method and the signal injection method, are proposed to perform such a measurement. The insertion loss method utilizes the EMI emission as a signal source and derives the source impedance by measuring the emission attenuation caused by an inserted impedance. The signal injection method injects a signal to the power supply and measures the response. The insertion loss method is verified experimentally both for common mode and differential mode, The signal injection method for common mode source impedance measurement is experimentally verified. That for differential mode source impedance measurement requires a faster equipment and is not fully verified. An EMI filter is usually characterized in the manufacturer’s catalog by its attenuation in a standard system (50Ω source impedance and 50Ω load impedance). The effectiveness of the filter in a practical system may significantly deviate from the manufacturer’s data. To provide the users with practically useful information, a scheme to characterize the EMI filter, the impedance matrix approach is proposed. This approach takes parasitic effect into consideration and the parameters can be measured relatively easily. The approach is verified experimentally by applying a commercial EMI filter to a power supply and comparing the predicted attenuation with the measured one. / Master of Science

Baigiamajame darbe suprojektuotas ir ištirtas programuojamas aukštosios įtampos maitinimo šaltinis. Įvade išnagrinėti programuojami aukštosios įtampos maitinimo šaltiniai, jų taikymo ir panaudojimo sritys. Taip pat išnagrinėti GPIB sąsajos privalumai ir trūkumai. Analitinėje dalyje smulkiai nagrinėjama maitinimo šaltinių sandara ir veikimo principas. Pateikiamos kai kurių maitinimo šaltinio sandaros elementų grandinių schemos. Taip pat analitinėje dalyje smulkiai išnagrinėtas GPIB sąsajos veikimo principas ir šios sąsajos taikymo galimybės. Projektinėje dalyje ištirtas aukštosios įtampos maitinimo šaltinis ir jo charakteristikos, pateikta išėjimo signalo įtampos forma. Taip pat šioje dalyje suprojektuota GPIB sąsaja maitinimo šaltiniui ir pateiktas programinės įrangos algoritmas. Darbą sudaro 6 dalys: įvadas, analitinė dalis, projektinė dalis, išvados ir pasiūlymai, literatūros sąrašas. Darbo apimtis: 57 p. teksto be priedų, 56 pav., 4 lent., 32 bibliografiniai šaltiniai. / In this final project we made research of high voltage programmable power supply. In the preface of this project the high voltage power supplies, there application and using areas are described. Also in this part of the work we describe GPIB interface advantages and disadvantages. In the analytic part we analyze power supply structure and working principles in detail. We give some power supplies structure elements schemes. Also in this part of work we analyze GPIB interface working principle and applying possibilities in detail. In the design part of the work we made a research of high voltage power supply, its characteristics and we give outgoing signal form in pictures. Also in this part we design GPIB interface for high voltage power supply and algorithm of software. Structure: introduction, analytical part, design part, conclusions and suggestions, references.

<p>The development of a deuterium-deuterium/ tritium-deuterium (D-D/ D-T) pulsed neutron generator based on the principle of the Plasma Immersion Ion Implantation (PI3) technique is presented, in terms of investigating development of a compact system to generate an ultra short burst of mono-energetic neutrons (of order 1010 per second) during a short period of time (&lt / 20&mu / s) at repetition rates up to 1 kHz. The system will facilitate neutron detection techniques, such as neutron back-scattering, neutron radiography and time-of-flight activation analysis.</p> <p><br /> Aspects addressed in developing the system includes (a) characterizing the neutron spectra generated as a function of the target configuration/ design to ensure a sustained intense neutron flux for long periods of time, (b) the system was also characterised as a function of power supply operating conditions such as voltage, current, gas pressure and plasma density.</p>

Die elektrische Energieform gewinnt im Kraftfahrzeug wegen ihrer Nutzungsvielfalt und sehr guten Steuerbarkeit für die Realisierung neuartiger Funktionen zunehmend an Bedeutung. Voraussetzung für ihren Einsatz ist eine zuverlässige und effiziente Bereitstellung durch das Kfz-Energiebordnetz. Dafür ist ein intelligentes Energiemanagement erforderlich, welches mit geeigneten Strategien die Leistungsflüsse im Energiesystem koordiniert. In dieser Arbeit werden die beiden Entwurfsziele der Zuverlässigkeit und der Effizienz bei der Entwicklung von elektrischen Energiemanagement-Strategien systematisch betrachtet. Es erfolgt eine Beschreibung und Zuordnung der einzelnen Ziele und Maßnahmen anhand der Energieflüsse und Wirkungsketten. Ein Schwerpunkt bildet dabei die Beherrschung von Lastwechseln im Bordnetz. Für Aussagen hinsichtlich einer effizienten Erzeugung elektrischer Energie erfolgt eine Untersuchung der Energiewandlungskette anhand analytischer Methoden und mit Hilfe einer simulationsgestützten Optimierung. Ein weiterer Fokus der Arbeit liegt in der Betrachtung zur Anwendung ökonomischer Modelle für eine Energiekoordination. Es werden die theoretischen Grundlagen der Mikroökonomie zusammengestellt und mögliche Funktionsstrukturen eines einseitigen und zweiseitigen Allokationsmechanismus verglichen und bewertet. Abschließend zeigen experimentelle Untersuchungen an einem Bordnetzprüfstand zum Lastwechselverhalten und die Integration eines Energiemanagement-Systems den praktischen Bezug zum realen System.

Power conservation has become a high priority to South African industries due to recent environmental assessments and electricity price hikes. This research aims to demonstrate to Industry the many simple and cost effective ways to increase their industrial efficiency with simple modifications, as well as making them more aware of common assembly errors that significantly increase power consumption. This has been accomplished with the design, construction and testing of a test rig capable of producing the desired test results which simulate Industry usage. A test rig was required to test certain energy efficient equipment. This dissertation contains an explanation of the tests required, as well as how they were conducted. These test requirements directed the design outcomes of the test rig. Due to the variety of equipment to be tested, and the accuracy required, the test rig had to be fully adjustable. The design process is explained in this dissertation, along with relevant theory with regard to the testing procedures. The testing procedures were designed to be as accurate as possible. The setup equipment and procedure is briefly explained to ensure an understanding of the capabilities of the test rig. This dissertation contains the results obtained from testing a variety of couplings, belts and motors under different conditions. The results obtained show the difference between the efficiency of a standard motor and that of a high efficiency motor. The efficiency comparison of the Poly V TM, Poly Chain® and SPB V-belts showed very distinct advantages and disadvantages of each belt. The coupling testing was conducted under conditions of misalignment, and resulted in distinct differences in the efficiencies of each coupling at different degrees of misalignments. The couplings tested were the Fenaflex®, the Quick-Flex®, and the Fenagrid® coupling. All results obtained were analyzed and discussed in the relevant sections. The results obtained showed that the high efficiency motor is significantly more efficient than the standard motor at full load, although at low loading, the motor efficiencies were very similar. The coupling tests showed the negative effects misalignment has on the efficiency of the Quick-Flex® and Fenagrid® coupling as well as the capability of the Fenaflex® coupling to withstand the effects of large misalignments without significant efficiency loss. v The belt testing revealed the advantages and disadvantages of each type of belt used. This showed that although the synchronous belt did not lose efficiency with decreased tension, it became unstable, and was difficult to keep on the pulley if not aligned correctly. The V-belts can handle low tension well. Prolonged use of the belts can cause them to stretch, lowering the tension into a “danger zone” that will cause the belts to slip. This slip can damage the belt and pulley. At the lower tension of the V-belt, although the efficiency increases slightly, the vibration of the slack side of the belt is significant, and can be dangerous as the belt could jump off the pulley. The Poly V TM belt has some of the advantages of the V-belt, except that it is unable to maintain its friction at low tension, as the belt width prevents it from being wedged into the grooves like the V-belt. The fluid coupling tests showed that the shock loading on a high inertia system can be significantly reduced with the aid of a fluid coupling. The reduced shock loading can reduce energy consumption, and increase the life of electric motors and the equipment that they drive by preventing excessive overloading. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2011.

<p>The development of a deuterium-deuterium/ tritium-deuterium (D-D/ D-T) pulsed neutron generator based on the principle of the Plasma Immersion Ion Implantation (PI3) technique is presented, in terms of investigating development of a compact system to generate an ultra short burst of mono-energetic neutrons (of order 1010 per second) during a short period of time (&lt / 20&mu / s) at repetition rates up to 1 kHz. The system will facilitate neutron detection techniques, such as neutron back-scattering, neutron radiography and time-of-flight activation analysis.</p> <p><br /> Aspects addressed in developing the system includes (a) characterizing the neutron spectra generated as a function of the target configuration/ design to ensure a sustained intense neutron flux for long periods of time, (b) the system was also characterised as a function of power supply operating conditions such as voltage, current, gas pressure and plasma density.</p>

Magister Scientiae - MSc / The development of a deuterium-deuterium/ tritium-deuterium (D-D/ D-T) pulsed neutron generator based on the principle of the Plasma Immersion Ion Implantation (PI3) technique is presented, in terms of investigating development of a compact system to generate an ultra short burst of mono-energetic neutrons (of order 1010 per second) during a short period of time (< 20μs) at repetition rates up to 1 kHz. The system will facilitate neutron detection techniques, such as neutron back-scattering, neutron radiography and time-of-flight activation analysis. Aspects addressed in developing the system includes (a) characterizing the neutron spectra generated as a function of the target configuration/ design to ensure a sustained intense neutron flux for long periods of time, (b) the system was also characterised as a function of power supply operating conditions such as voltage, current, gas pressure and plasma density. / South Africa

No description available.

This master´s thesis describes switch mode power supply. The aim of this master´s thesis is the design and the construction of the switch mode power supply, which will be used as a laboratory tool.